With the introduction of consumer premises based access node, e.g. Home Node B (HNB), Home eNode B (HeNB), Femto Cell base station, Atto Cell base station or home base station, 3GPP also created use cases for the Local IP Access (LIPA) and Selected IP Traffic Offloading (SIPTO) (Non Patent Literature 1), where the Packet Data Network (PDN) Gateway PGW) is collocated or close to the HNB/HeNB. With LIPA or SIPTO, a User Equipment (UE) accessing the network via cell/cells of a HNB/HeNB can obtain access to network that is connected or near to the HNB/HeNB besides the operator's core network. For example, LIPA allows direct access to the home based network or general Internet without going through the operator's core network.
In certain cases, there may be multiple HNB/HeNBs deployed around the same area, e.g. in an enterprise/campus network deployment. These HNB/HeNBs are connected to the same local network. In such cases, mobility between the HNB/HeNBs is to be supported, such that service will not be interrupted when user moves around. For example, when a UE moves between cells of the HNB/HeNBs belonging to the same enterprise network, it should be able to continuously downloading files and accessing emails. This can be achievable using the existing mobility procedures defined in (Non Patent Literature 2).